physiology 3 renal

Question 1

Filtered sodium is about

Answer 1

26000 mmol/day

Question 2

mmol of Na+ excretion is excreted in urine each day.

Answer 2

150 mmol

Question 3

how much of the filtered Na reabsorbed?

Answer 3

99.50%

Question 4

Does the filteration fraction with an increase in sodium

Answer 4

nope

Question 5

What increases with an increas in sodium intake

Answer 5

RPF and GFR + excretion of sodium

Question 6

a decrease in sodium intake increases

Answer 6

FF

Question 7

Which decreases more? The RPF or GFR?

Answer 7

RPF

Question 8

The ability of the tubules to increase reabsorption rate in response to increased GFR and tubular load.

Answer 8

glomerutubular balance

Question 9

This balance minimizes the effect of changes in GFR and prevents overloading of tubules.

Answer 9

purpose of glomerutubular balance

Question 10

The proximal tubule tends to reabsorb a constant proportion (65%) of the glomerular filtrate rather than a constant amount.

Answer 10

just know it.

Question 11

eflex vasoconstriction or dilatation of afferent arteriole in response to changes in tubular flow.

Answer 11

Tubulo-glomerular feedback

Question 12

Funtion of TGF

Answer 12

Increased flow rate in late ascending limb of loop of Henle and first part of distal convoluted tubuleàdecreases GFR (decreased flow increases GFR)

Question 13

ThesensorforTGFisthe

Answer 13

macula densa

Question 14

High flow rate and high NaCl in the macula densa results in

Answer 14

release of substances like (ATP) à generate adenosine, a potent vasoconstrictor of afferent arteriole àdecrease GFR.

Question 15

which substances enhance TGF, and which blunt it

Answer 15

angio 2 + ROS enahnce, NO blunts

Question 16

what increases when increase when renal arterial pressure increases.

Answer 16

sodium and water excretion

Question 17

entral component in the long term regulation of arterial blood pressure.

Answer 17

pressure natriuresis

Question 18

Sympathetic nerve terminals affect sodium reabsorption in the kidney by

Answer 18

releasing norepinephrine (NE) which decreases Na+ and water

Question 19

what does renin do?

Answer 19

– Increasedsympathetictone.
– Decreasedrenalperfusion(lessstretch). – Decreased delivery of NaCl to macula
densa (Hyponatremia).

Question 20

Renin release is inhibited by

Answer 20

angi2

Question 21

converts angiotensinogen to
angiotensin I (AI).

Answer 21

renin

Question 22

angio 2 stimulates 2 transporters, name them

Answer 22

Direct stimulation Na+ reabsorption in most parts of the renal tubules (activate Na-K pump).
• Direct stimulation of Na+-H+ antiporter in proximal tubules.

Question 23

Aldosterone increases Na+ reabsorption, how?

Answer 23

– Rapid:increasestheactivityofpre-existing
ENaCs and Na-K ATPase.
– Late:increasesnumberofapicalNa+
channels and basolateral Na-K pumps.

Question 24

Excess aldosterone causes

Answer 24

hypokalemia

and increases ECF volume and BP

Question 25

ANP release is stimulated by

Answer 25

atrial distension due to volume expansion

Question 26

– Directly increases GFR via afferent arteriolar
dilation and efferent constriction.
– Inhibits renin and aldosterone secretion.
– Inhibits Na+ reabsorption in deep medullary collecting ducts.
– Increases Na+ and water excretion.

Answer 26

actions of ANP

Question 27

• Formed locally in the kidneys from circulating L-dopa.

Answer 27

dopamine

Question 28

– In low doses causes renal vasodilatation and increases Na+ excretion.
– Increases sodium excretion by diminishing reabsorption in the proximal tubule and collecting tubule.
– DirectlyinhibitsapicalNa-Hexchanger and basolateral Na-K pump primarily in the proximal tubule.

Answer 28

actions of dopamine

Question 29

It inhibits Na+ reabsorption through ENaCs, autocrine function on the collecting ducts

Answer 29

endothelin

Question 30

inhibits Na+ reabsorption in the thick ascending limb and collecting ducts, produced locally in the kidney

Answer 30

prostaglandins